The Cincinnati Clinical Center of the National Heart Lung and Blood Institute's Growth and Health Study (NGHS-I, HC 55025), in conjunction with its collaborating centers, proposes an extension to the current study so that the cohort being followed for five years from ages 9 and 10 years to ages 13 and 14 years can be followed through the entire pubertal period. The goals of the NGHS initiative were to describe and explain a) the greater incidence of obesity in black females during adolescence and b) its association to major cardiovascular disease (CVD) risk factors. The Cincinnati Center, therefore, proposes to measure in the cohort of girls for three more years: 1) antecedent factors (e.g., diet, exercise, and psychosocial factors); 2) body habitus (e.g. height, weight, skinfolds, and circumferences, and maturation status); and 3) CVD risk factors affected by body habitus (e.g. blood pressure and lipids). Parents and guardians of the girls will also be evaluated. The proposed extension is described in detail in the collaborative grant application. The Cincinnati Center has conducted a school-based study in NGHS-I: subjects were enrolled from the fourth and fifth grade classes of public and parochial schools in Cincinnati and surrounding Hamilton County selected from to be racially, geographically, and socioeconomically representative of the area. The Cincinnati Center enrolled 867 students, 430 white and 437 black. At the end of NGHS-I, the girls will be in grades 8 and 9. In the extension (NGHS-II), subjects will be in grades 9-12. The Cincinnati Center proposes to continue a school-based study, though some subjects will have to be seen at Children's Hospital or their home for a variety of reasons (e.g. moving outside the area, but within 100 miles of Cincinnati, transferring to a school which will not cooperate with the study (this has not occurred to date), or dropping out of school.) The Cincinnati Center will continue to use basically the same staff, techniques, and incentives used in NGHS-I. Using these methods, the Cincinnati Center, like its collaborating partners, has achieved an excellent retention rate in the cohort: (89%) were still in the study at the end of Year 4.